import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        Solution solution=new Solution();
        String s=scanner.next();
        System.out.println(solution.longestPalindrome(s));
    }

    public static void main2(String[] args) {
        Scanner scanner=new Scanner(System.in);
        Solution2 solution2=new Solution2();
        int n=scanner.nextInt();
        int[] m=solution2.countBits(n);
        for (int i = 0; i <=n ; i++) {
            System.out.println(m[i]);
        }
    }

    public static void main1(String[] args) {
        Scanner scanner=new Scanner(System.in);
        Solution1 solution1=new Solution1();
        List<Integer>array=new ArrayList<>(100);
        int n=scanner.nextInt();
        int m=scanner.nextInt();
        int k=scanner.nextInt();
        for(int i=0;i<n;i++){
            array.add(scanner.nextInt());
        }
        System.out.println(solution1.countInterestingSubarrays(array, m, k));
    }
}

class Solution1 {
    public long countInterestingSubarrays(List<Integer> nums, int modulo, int k) {
        long res=0;



        return res;
    }
}

class Solution2 {
    public int[] countBits(int n) {
        int[]res=new int[n+1];
        for(int i=0;i<=n;i++){
            int x=i;
            while(x!=0){
                res[i]+=x%2;
                x/=2;
            }
        }
        return res;
    }
}

class Solution {
    public String longestPalindrome(String s) {
        int n=s.length();
        int l=0,r=0;
        String string;
    }
}